ULLMER, J. H. The scientific method of Sir William Petty. Erasmus Journal for Philosophy and Economics, [S. l.], v. 4, n. 2, p. 1-19, 2011. DOI: 10.23941/ejpe.v4i2.78. Disponível em: https://ejpe.org/journal/article/view/78. Acesso em: 30 sep. 2020.